1. Field of the Invention
The present invention is related to a high voltage switch circuit of a semiconductor device and particularly, to a high voltage switches circuit capable of rapidly discharging a high voltage.
2. Discussion of Related Art
A semiconductor device needs a high voltage pumped over an input power supply voltage, in which a high voltage transfer switch is required to pass the high voltage. In a conventional NAND flash memory, a pumping bias voltage is transferred to a wordline as a target voltage during a program operation or a read operation, for which a gate bias is boosted up from a floating state with a coupling level at a junction of a pass transistor by applying a bias voltage to the junction of the pass transistor at a time and thereby the wordline is charged with the bias voltage without a voltage drop.
However, after transferring the target bias voltage, the gate voltage of the pass transistor gradually decreases for discharging the bias voltage, so that the high voltage generated internally (i.e., applied to the pass transistor) drops when the voltage level transferred goes to a logical low. Further, relative to a higher frequency operation in a semiconductor device, such a discharging time for the bias voltage increases to cause a disadvantage for the device.